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What Causes Leg Swelling When On Levothyroxine For Hypothyroidism?
Question: I currently have been prescribed 75 mcg 1/day for hypothyroidism - Levothyroxine. I had been taking it for 2 years and suddenly started to feel agitated so reduced my own dose-not doctor-to 1/2 of that 75 mcg pill. For two months now I have been lower dose but starting to feel lethargic again and falling asleep constantly. I also noticed that my legs started to swell about three weeks ago. It is not water weight-but hard feeling-not in ankles or toes just in calf from knee to ankle. So I went back to the regular dose of 75 mcg three days ago. It seems to be helping the swelling by about half. I have recently started computer job sitting longer intervals as well. But I really think it is related to the thyroid. Can this be a symptom of hypothyroidism or the levothyroxine????
Brief Answer:
Thyroid
Detailed Answer:
Levothyroxine is not known to cause such swelling. As you have yourself surmised quite rightly, untreated or inadequately treated hypothyroidism can cause such swelling in the legs. If your diagnosis is correct and if you truly have a permanently under active thyroid then an insufficient dose of levothyroxine can induce leg seeking. The key test to ascertain this is a simple non fasting blood sample for TSH. It should ideally be kept between 0.4 to 2.5 on treatment with levothyroxine, although there are a few exceptions in select circumstances where the target is more lenient (ie upto 5). However if the TSH is well within the normal range then it is extremely unlikely that the swelling is due to hypothyroidism, and you may wish to consider other causes by consulting your primary physician
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
The symptoms of the leg swelling seemed to coincide with my deciding to reduce my own dosage-My doctor recommended 75mcg and I decided on my own about two months ago to reduce it to 1/2 of the pill per day after 2 years at 75 mcg. Within 1-2 months my legs just began swelling. The change is the levothyroxine to a lower dose is the only thing that I can equate that changed at the same time. From what you state, it would appear that my having lowered my own dosage with the consultation of my doctor has produced a situation in which my thyroid is undermedicated at this point. I have gone back on my regular 75mcg for the past two days and am going in for my annual testing of Thyroid function in two weeks. I do have an underactive thyroid as diagnosed over two years ago by my doctor. So I think I have complicated my own situation by cutting my own dose in half, thus prompting the leg swelling which I had never experienced before. Is this your analysis?Please note that I myself decided to lower my own dosage of levothyroxine and have not had my thyroid functioning retested for the past year. So it would appear that I most likely am in a hypothyroid state as I have too low a dosage of levothyroxine. Correcct?
Brief Answer:
Follow up
Detailed Answer:
Quite likely the case, as deduced by you. It is important to take the prescribed dose regularly and periodically check the blood levels to ensure adequacy of dosage which can change over time, especially in the first several months after diagnosis when the Endocrinologist attempts to safely arrive at the dose needed by your body.
Swelling of the legs is one of the many signs that indicates the possibility of an underactive thyroid or one that is under treated with a dose that is below the needs of the individual
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thank you very much. I will be having my complete blood work done in a couple of weeks. I am quite certain that his is what is suddenly causing the swelling since it only started about 1 month after I lowered by own dosage. Thank you for your thoughts and confirmation. Sincere thanks.
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